A convenience base class for generic services that are schedulable. It is
not difficult to implement Schedulable directly, but it does involve a
fair amount of code. This base class is a simple implementation of
Schedulable that is suitable for most services that want to implement
Schedulable.

Subclasses need only implement performScheduledTask() to be
schedulable.
It is recommended that the jobName and
jobDescription properties be configured on this
component. Subclasses can also provide default values for these in their
doStartService() methods if desired.
Nota Bene: the schedule related properties are only consulted when
startScheduledJob() is called. If any of these properties
change, you can call stopScheduledJob() and
startScheduledJob() to pick up the changes.